Aromatic polyamideimide resins are plastic materials excellent in heat resistance, mechanical strengths, electrical properties and chemical resistance, and have been so far used as varnishes, films, etc. An aromatic polyamideimide resin is produced typically by a method in which an aromatic tricarboxylic acid anhydride and a diisocyanate are reacted in a solvent or a method in which an aromatic tricarboxylic acid anhydride halide and a diamine are reacted in a solvent. However, the polyamideimide resins produced by these methods are, though suitably used in the preparation of varnishes, cast films, etc., not suitable for use in melt molding including injection molding because of its inferior melt moldability.
In the specification of U.S. Pat. No. 4,313,868, there is proposed a copolyamideimide for use in injection-molding, said copolyamideimide having the following recurring polyamideimide unit (I) and recurring polyamide unit (II), ##STR2## wherein R is a divalent aromatic hydrocarbon radical having about 6 to about 20 carbon atoms or a divalent hydrocarbon which is bound to a group selected from the group consisting of --O--, methylene, --CO-- and --SO.sub.2 -- either directly or via a stable linkage, and X is a divalent aromatic radical, the unit (I):unit (II) molar ratio being 80:20 to 20:80.
Compared to a polyamideimide resin free of the recurring unit (II), the above copolyamideimide has improved melt moldability, but a flow starting time in melt-molding of the copolyamideimide is close to a decomposition temperature in melting of the copolyamideimide, so that good molding of the copolyamideimide remains unachieved.
Japanese Laid-open Patent Application (Kokai) No. 59-8,755 (8,755/1984) proposes an abrasion-resistant resin molding material comprising an intimate mixture of
(a) 30 to 90% by weight of a polyamideimide resin, PA1 (b) 10 to 70% by weight of graphite and/or molybdenum disulfide, and PA1 (c) 0 to 30% by weight of at least one member selected from a polyphenylene sulfide resin, a polyamide resin and an aromatic polyester resin which have better flowability than the polyamideimide resin. PA1 (A) an aromatic copolyamideimide containing 5 to 95 mol % of a recurring unit represented by the formula (1) and 5 to 95 mol % of at least any one of a recurring unit represented by the formula (2) and a recurring unit represented by the formula (3), provided that the total amount of these three recurring units is 100 mol %, ##STR5## wherein Ar in the formula (1) denotes a trivalent aromatic group containing at least one 6-membered carbon ring, Ar.sub.1 in the formula (2) denotes a divalent aromatic group containing at least one 6-membered carbon ring, R.sub.1 in the formula (3) denotes a divalent aliphatic group, and R in the formulas (1), (2) and (3) denotes a divalent aromatic or aliphatic group, and PA1 (B) a polyester resin, the weight ratio of the aromatic copolyamideimide (A) and the polyester resin (B) ((A)/(B)) being 95/5 to 5/95, and the aromatic copolyamideimide (A) being prepared by conducting a polymerization reaction of an aromatic tricarboxylic acid anhydride and at least any one of an aromatic dicarboxylic acid and an aliphatic dicarboxylic acid with a diisocyanate compound in plural steps such that in the first step the polymerization reaction is conducted in a temperature range of 50.degree. to 110.degree. C. and in the second and subsequent steps the polymerization reaction is conducted in a temperature range of higher than 101.degree. C. but not higher than 200.degree. C. PA1 (A) an aromatic copolyamideimide containing 10 to 30 mol % of a recurring unit represented by the formula (1) and 70 to 90 mol % of at least any one of a recurring unit represented by the formula (2) and a recurring unit represented by the formula (3), provided that the total amount of these three recurring units is 100 mol %, and PA1 (B) a polyester resin, the weight ratio of the aromatic copolyamideimide (A) and the polyester (B) ((A)/(B)) being 95/5 to 5/95. PA1 (A) an aromatic copolyamideimide containing 5 to 95 mol % of a recurring unit represented by the formula (1) and 5 to 95 mol % of at least any one of a recurring unit represented by the formula (2) and a recurring unit represented by the formula (3), provided that the total amount of these three recurring units is 100 mol %, and PA1 (B) a polyester resin (B), the weight ratio of the aromatic copolyamideimide (A) and the polyester (B) ((A)/(B)) being at least 10/90 but less than 50/50. PA1 (A) an aromatic copolyamideimide containing 5 to 95 mol % of a recurring unit represented by the formula (1) and 5 to 95 mol % of at least any one of a recurring unit represented by the formula (2) and a recurring unit represented by the formula (3), provided that the total amount of these three recurring units is 100 mol %, and PA1 (C) a polyphenylene sulfide resin, the weight ratio of the aromatic copolyamideimide (A) and the polyphenylene sulfide resin (C) ((A)/(C)) being 95/5 to 5/95, and the aromatic copolyamideimide (A) being prepared by conducting a polymerization reaction of an aromatic tricarboxylic acid anhydride and at least any one of an aromatic dicarboxylic acid and an aliphatic dicarboxylic acid with a diisocyanate compound in plural steps such that in the first step the polymerization reaction is conducted in a temperature range of 50.degree. to 110.degree. C. and in the second and subsequent steps the polymerization reaction is conducted in a temperature range of higher than 110.degree. C. but not higher than 200.degree. C. PA1 (A) an aromatic copolyamideimide containing 10 to 30 mol % of a recurring unit represented by the formula (1) and 70 to 90 mol % of at least any one of a recurring unit represented by the formula (2) and a recurring unit represented by the formula (3), provided that the total amount of these three recurring units is 100 mol %, and PA1 (C) a polyphenylene sulfide resin, the weight ratio of the aromatic copolyamideimide (A) and the polyphenylene sulfide resin (C) ((A)/(C)) being 95/5 to 5/95. PA1 (A) an aromatic copolyamideimide containing 5 to 95 mol % of a recurring unit represented by the formula (1) and 5 to 95 mol % of at least any one of a recurring unit represented by the formula (2) and a recurring unit represented by the formula (3), provided that the total amount of these three recurring units is 100 mol %, and PA1 (C) a polyphenylene sulfide resin, the weight ratio of the aromatic copolyamideimide (A) and the polyphenylene sulfide resin (C) ((A)/(C)) being at least 10/90 but less than 50/50. PA1 (A) an aromatic copolyamideimide containing 5 to 95 mol % of a recurring unit represented by the formula (1) and 5 to 95 mol % of at least any one of a recurring unit represented by the formula (2) and a recurring unit represented by the formula (3), provided that the total amount of these three recurring units is 100 mol %, and PA1 (D) a thermoplastic resin capable of forming an anisotropic molten phase, the weight ratio of the aromatic copolyamideimide and the thermoplastic resin (D) ((A)/(D)) being 95/5 to 5/95. PA1 (a) a method in which an aromatic tricarboxylic acid anhydride and an aromatic dicarboxylic acid and/or an aliphatic dicarboxylic acid are reacted with a diisocyanate compound in an amide group-containing solvent or an amide group-free solvent to produce the copolymer (A). PA1 (b) a method in which an aromatic tricarboxylic acid anhydride halide and an aromatic dicarboxylic acid dihalide and/or an aliphatic dicarboxylic acid dihalide are reacted with a diamine compound in the above solvent to produce the copolymer (A). PA1 (c) a method in which an aromatic tricarboxylic acid anhydride and an aromatic dicarboxylic acid and/or an aliphatic dicarboxylic acid are reacted with a diamine compound in the presence of a polycondensation catalyst such as phosphoric acid or a phosphorous acid ester. PA1 (a) a method in which the liquid crystal polymester is produced by a polycondensation reaction from a dicarboxylic acid, an acetic acid ester of an aromatic dihydroxy compound and an acetic acid ester of an aromatic hydroxy acid. PA1 (b) a method in which the liquid crystal polymester is produced by a polycondensation reaction from a dicarboxylic acid diphenyl ester, an aromatic dihydroxy compound and an aromatic hydroxy acid phenyl ester.
The above polyamideimide resin (a) is an aromatic polymer which has 30 to 100 mol % of a recurring unit represented by the formula (III), ##STR3## and which may have less than 70 mol % of a polyamide unit represented by the formula (IV). ##STR4## Ar in the formula (III) is a trivalent aromatic group containing at least one 6-membered carbon ring. R in the formulas (III) and (IV) is a divalent aromatic group and/or a divalent aliphatic group. Ar' in the formula (IV) is a divalent aromatic or aliphatic group containing at least one 6-membered carbon ring.
In this document, it is described that at least one member of the resin (c) selected from the polyphenylene resin, the polyamide resin and the aromatic polyester resin is contained in the molding material as a good fluidity imparting agent.
However, said document neither discloses nor suggests this invention.